This invention relates to an implantable anti-reflux fluid displacement peritoneovenous shunt used to transfer an unwanted accumulation of body fluids from a body cavity to a site where they can be processed by the body. The primary use for the shunt is in the treatment of patients with ascites by the displacement of accumulated peritoneal cavity fluid into the systemic venous circulation.
This application is related to our copending U.S. application Ser. No. 598,243, filed Apr. 4, 1984, entitled Compression Pump-Catheter and directed to a manually operable ascites shunt. The disclosure of that application is incorporated herein by reference. The device of the aforesaid application is a peritoneovenous shunt in which ascites fluid is transferred from the peritoneum to the vasculature via a manually operated compression pump. That device is not an alternative for certain patients who require peritoneovenous shunting but for a variety of reasons are unable to perform the pumping mechanics. The present invention is directed to a peritoneovenous shunt which features automation of the earlier design, thus expanding the benefit of this therapy to a broader population of patients and providing greater convenience to existing patients.
As described in application Ser. No. 598,243, there is evidence that ascites occurs with the obstruction, or increase in pressure, of hepatic lymphatics with a subsequent oozing of lymphatic fluid from the surface of the liver. If the fluid flux is high, especially in an individual with liver disease and portal venous system hypertension, there is inadequate re-absorption of this fluid and it accumulates within the peritoneal cavity.
In addition to the discomfort and pressure problems associated with massive abdominal distention due to ascites, patients with ascites are more prone to develop reflux esophagitis, respiratory failure, abdominal wall hernia defects, renal failure, and an increased susceptibility to infections.
Besides its use in the management of ascites, the shunt of this invention can, with modest modifications, be utilized for the transfer of other body fluids, e.g., the displacment of brain ventricular fluid in hydrocephalus to either the right atrium of the heart or to the peritoneal cavity.